Micronecta (Unguinecta) melanochroa, Nieser & Chen & Yang, 2005

Nieser, Nico, Chen, Ping-ping & Yang, Chang Man, 2005, A New Subgenus And Six New Species Of Nepomorpha (Insecta: Heteroptera) From Yunnan, China, Raffles Bulletin of Zoology 53 (2), pp. 189-209 : 202-203

Micronecta (Unguinecta) melanochroa , new species

( Figs. 42-50 )

Material examined. – Holotype ( ZRC) - macropterous male, CHINA: Yunnan, Xishuangbanna, Lancang river, 24 km from Jinghong , potholes on large boulder, 10 m above river, 6 Jun.2002, coll. C. M. Yang & D.Q. Li.

Paratypes, same data as holotype, 1 male (teneral, NCTN), 1 female ( ZRC). All macropterous .

Description. – Macropterous form, based on specimens in alcohol. In dorsal view, a dark brown, medium sized, rather parallel-sided species, with its greatest width just anteriorly of the caudal apex of claval commissure.

Dimensions (measurements of the holotype mentioned first). Length, male 2.31-2.38, female 2.32; width, male 1.09 (paratype not measured), female 1.05; width of head, male 0.83-0.82, female 0.82; synthlipsis, male 0.42-0.40, female 0.43; posterior width of an eye, male 0.25-0.22, female 0.21; width of pronotum, male 0.92-0.90, female 0.90; ocular index, male 2.05-1.90, female 2.21.

Colour. Dorsally generally dark brown; head yellowish, eyes castaneous, rostrum dark brown to blackish; clypeal area light to medium brown. Pronotum unicolorous medium brown except for caudolateral angles and posterior margin broadly (0.1) yellow; scutellum brown. Hemielytra medium brown but, when closed, appearing dark brown due to the underlying dark grey abdominal dorsum, without darker patches; distal margin of right membrane yellowish; embolium yellowish to light brown with a thin blackish stripe near inner margin; without brown patches at costal margins; hyaline mark at base of clavus short, about 0.12 long, its V-shape obscured by reddish marking. Thorax and abdomen ventrally dark greyish brown. Legs pale yellowish with some small dark brown marks, notably in distal half of pala and at distal edge of middle tarsus.

Structural characteristics. Length 2.1-2.2 times width. Head slightly narrower than pronotum, synthlipsis 1.7-2.0 times as wide as the posterior margin of an eye. Pronotum well developed, dorsally convex with well developed lateral margins, 2.3-2.4 times as wide as long. Hemielytra smooth with only sparse and small pale spinules, mostly in distal half of corium. Spines laterally on abdominal segments: VI two short, three long and a long bristle ( Fig. 44 ); VII five short, three long; VIII three short two very long hair-like on left part, and five short two very long hair-like on right part. Pala ( Fig. 49 ) with five dorsal bristles; upper row of palm with about 18 bristles the distal one somewhat larger; ventral row with about 32 very fine bristles, the distal one conspicuously larger than the proximal ones, developed into a secondary claw. Leg measurements as in table 1.

Male. Fore leg ( Fig. 49 ): femur with two apical spines, of which one very small, and one in apical third, three spines in basal half; in addition, there are some very small spines along ventral margin, several of which were represented by scars only in the microscopic slide of the paratype; tibia with three long spines in apical third; palar claw triangular ( Fig. 50 ). Prestrigilar lobe ( Fig. 46 ) poorly differentiated, apically broadly rounded. Strigil ( Figs. 44, 45 ) oval, with a distinct stalk and one comb with about 50 densely packed teeth. Median lobe of seventh abdominal sternite ( Fig. 47 ) well developed, with a rounded apex and two bristles on its surface. Free lobe of left part of segment eight ( Fig. 48 ) elongate, apical margin sinuate; with about 22 bristles in lateroapical part which is slightly produced. Right paramere ( Fig. 42 ) with its shaft somewhat swollen in the middle and with a blunt apex, basal process with about 20 stridulatory ridges. Left paramere ( Fig. 43 ) with a narrow shaft.

Female. Palar claw bristle-like, twice as thick as the apical bristle in ventral row.

Brachypterous form unknown.

Etymology. – Melanochroos (Greek adjective, meaning of dark colour) refers to the dark colour of this species.

Comparative notes. – This species is closely related with the other species of subgenus Unguinecta : M. khasiensis , M. matsumurai , M. polhemusi , and M. waltoniana . In males the triangular palar claw of M. melanochroa is distinctive, in M. khasiensis and M. waltoniana the male palar claw is narrow, virtually parallel-sided ( Hutchinson, 1940: Figs. 171, 180); in M. matsumurai it is narrowly clavate ( Miyamoto, 1965: ppl. 43 fig. c) and in M. polhemusi clavate ( Nieser, 2000: Fig. 21 ); in addition, the last two species have only about 23 bristles in ventral palmar row. The right paramere of M. matsumarai is more slender, and the right paramere of M. polhemusi has a distinct bulge at the base of the shaft. M. khasiensis and M. waltoniana have the shaft of the right paramere parallel-sided, not slightly swollen in the middle. With the key to SE Asian species ( Nieser, 2000) M. melanochroa might run to M. khasiensis .

FAMILY NEPIDAE

Figures

Figs. 42-48. Micronecta melanochroa, new species, paratype, male; 42) right paramere; 43) left paramere; 44) right part of tergite VI; 45) strigil, scale: 0.05 mm; 46) prestrigilar lobe; 47) mediocaudal lobe of sternite VII; 48) free lobe of left part of tergite VIII. Figs. 42-44, 46- 48, scale: 0.1 mm.

Figs. 49-50. Micronecta melanochroa, new species, paratype, male; 49) foreleg; 50) apex of pala. Scale: 0.05 mm.

Figs. 16-21. Micronecta janssoni, new species, paratype, male; 16) right paramere; 17) left paramere; 18) right part of tergite VI; 19) strigil, scale: 0.05 mm; 20) free lobe of left part of tergite VIII; 21) prestrigilar lobe. Figs. 16-18, 20-21, scale: 0.1 mm.